At the present time plumbing products are continually being required to consume less water without quality of performance. The plumping industry has adopted the term High Efficiency (“HE”) to describe the fixtures, whether urinal (HEU) or water closet (HEC). This has ushered in a whole new series of fixtures, i.e. the actual structural component such as urinal or toilet, typically ceramic china, designed to minimize water usage without adverse impact on performance. In addition these new fixtures, the components that control the flush have also seen changes to minimize water usage. In fact, as the amount of water being used to flush a fixture is reduced, the precision (such as the tolerances for the component) of the individual components becomes increasingly important. For example, a urinal designed to flush only a pint of water may not operate properly when utilized with a flush valve that provides a gallon of water per flush. Likewise, a one pint flush valve may not provide sufficient water to rinse a urinal fixture that was designed to have a one gallon flush volume.
In commercial applications fixtures are supplied with pressurized water in large diameter supply pipes using flushometers which afford quick reset and maximum power to completely clear out fixtures. The pressurized water and large diameter pipes allow the fixture to operate at high pressure and high flow rates. To deal with varying water supply conditions, popular flushometers come with a localized stop shut off attached to the flushometer valve. This localized stop shut off allows an installer to adjust the water volume in order to maximize bowl performance. In the past when flushometers delivered many gallons of water (˜3 to 5 gallons per flush) system requirements, such as water pressure and water flow, were fairly forgiving, as the flushometer had a longer cycle to overcome any problems with the water delivery system. With lower flow fixtures of today (1.6 gpf and lower) marginal water delivery system (upstream fresh water pipes) can cause a flushometer and fixture to perform poorly and in some instances fail to fully evacuate the bowl. In the prior art, the primary way to adapt to the water supply variables was the stop to adjust water flow.
Fitting and fixture manufacturers assume minimum pressures and flows within a system, but many fresh water delivery systems are operating marginally because of building expansion beyond the original piping limits and deteriorating water pressure/water flow. This will cause a flushometer and fixture to need a little adjustment because of the job site location in order to “dial in” the fixture to the unique operating infrastructure of the building's water supply system. At the opposite end of this problem are water agencies who discourage any adjustment whatsoever on a flushing device, but who also realize performance must not be sacrificed. Some local codes even go so far as to call out no ‘external’ adjustment, though external adjustments allow for some small opportunity for adjustment internal to the flush valve.
The sum total of a fixture's efficiency is not generally viewed only in terms of total gallons flushed, but the distribution of that total flush volume to maximize waste extraction while maintaining refill and trap seal of the bowl. Much has been taught over the years about the adjustments that can be made to the flushometer once one skilled in the art of installation has the valve on a particular job site and needs to dial it in to the unique operating characteristics of the building's water supply system. Adjustments to piston stroke and venting times have been taught and they cover a variety of approaches to affect the flush volume from a standard nominal volume of a particular valve. Flushometers are metering devices that not only deliver the correct total volume of water per cycle, but also deliver the correct incremental volume at the correct time during the short flush cycle. This is further accomplished with a relative fixed volume over a wide pressure range. This balance of water volume at the correct moment for the fixture hydraulics is achieved by a precise orchestration of contributing elements of the flushometer, beyond simple timing of the venting. Those skilled in the art realize changing the vent timing is but one way to effect flushing volume. Vent timing, fixed bypass size, refill, and flow are also key elements in controlling the water delivery to a fixture.
Also critical in the performance of these types of valves is the body, which is typically machined out of brass. It has been known in the art that varying the height at which the plunger strikes the relief valve stem will alter the venting time of the flush valve. Of great importance is the critical flushometer dimension between the handle assembly centerline (or more accurately, the centerline of the plunger tip that strikes the valve stem) in the flush valve assembly body handle opening and the seat for the relief valve. The position of the handle assembly within the handle opening also controls the height at which the plunger strikes against the relief valve stem (alternatively called the “gland” in the prior art) of the internal flushing kit (such as a piston or diaphragm kit) and controls the vent time of the control chamber and hence the amount of water per flush the valve will deliver.
In the current market there are water conservation service companies that audit commercial building's water consumption and come up with various approaches to saving water. These companies look to change out complete fittings and fixtures, while other companies conserve costs and only sell low flushing kits to put into the flushometer valves salvaging the existing installed fixtures. In the audit process, for those flushometer valves that do not have an external adjustment, alternate flushing kits have to be installed that “approximate” peak performance but sacrifice some marginal water savings. Each of these alternative kits provides a slight change to flush profile. It should be appreciated that in order to optimize each fixture, an installer may need to try several kits and utilize different kits in different fixtures. In the event that the underlying factors such as water flow changes, for example where a restroom is added to a building or where water consumption is greatly reduced, it would be necessary to change out the kits entirely. Some flow adjustment can be effected by throttling the control stop, but the primary water volume change is controlled by the new kit in the same flush valve assembly body.
For these service companies, having an adjustable setting on the valve (“Dial a Flush”) during install would be optimal. Having this dial a flush feature, old fixtures can be flushed effectively using less water and adjusting each fixture with just the right flow/volume and reduced gpf to evacuate on less water without installing a new fixture. The actual flushing parameter adjustment can be a continuum of options to meet the needs of each individual installation and not be limited to selected discrete flushing kits. The overall effect of water savings over a large population of fixtures in a building is thereby achieved.